SENSATIONS OF TASTE AND SMELL. 89 



B. Wipe the tongue dry and place upon it a bit of 



sugar. 



1. Can the sugar be tasted? 



2. To what condition must foods be brought 



in order to be tasted? 



3. What use of the saliva in the mouth does 



this suggest? 



4. Give a reason which may explain why sand 



is tasteless? 



C. Localization of taste sensations on the tongue. 



1 . Place a bit of sugar on the tip of the tongue ; 



another bit on the back of the tongue. 



a. In which case is the sweet taste more 



distinct ? 



b. Determine whether sweet substances 



are tasted more distinctly along the 

 middle of the tongue or at the edge. 



2. By using a bit of salt determine in the same 



way what region of the tongue is most 

 affected by saline substances. 



3. Prepare a strong solution of quinine by dis- 



solving 10 grains sulphate of quinine in 

 i oz. water by the aid of 5 drops sul- 

 phuric acid. Determine what portion 

 of the tongue is most sensitive to bitter 

 substances; the portion which is least 

 sensitive. 



